1. Field of the Invention
The present invention relates to a guaranteed isochronous services method and apparatus in bridged LAN. More particularly, the present invention relates to a guaranteed isochronous services method and apparatus in a bridged LAN that provides isochronous streams through bridges in a distributed network, filters the isochronous streams, and registers and authenticates stream groups so that the quality of service (QoS) can be improved.
2. Description of the Related Art
Generally, a bridge apparatus for a distributed network connects two or more local area networks (LANs) employing the same protocol. The bridge apparatus can also connect two segments to the same LAN.
IEEE 802.1 defines standard characteristic of a bridge. A basic bridge has a plurality of ports connected to a plurality of separated LANs. A frame received at one port is re-transmitted to another port. The bridge re-transmits all data frame irrespective of whether or not it is necessary. A learning bridge investigates a source field of the entire data frame found in each port to generate a table that defines each port as connected to a particular address.
Accordingly, if the data frame that is addressed to a destination is found in its own address table, the bridge transmits the data frame only to the port related to the address, unless the destination address is connected to the same port to input the data frame.
Various protocols have been introduced to provide optimal quality of service (QoS) when data is transmitted through the bridge in the distributed network. For example, the various protocols include differentiated services (Diffserv), integrated services (Intserv), and resource reservation protocol (RSVP).
In case of RSVP, subnet bandwidth managers (SBM) for LAN are variant, and the RSVP has a high complexity and is unfriendly to IEEE 802.1.
In case of the link layer reservation management protocol (LLRMP), which is a source initiated resource reservation, the integration with isochronous service is not considered.
In case of the listener station initiating protocol based on generic attribute registration protocol (GARP), no reservation is necessary and no justification exists.
In case of the listener station initiating protocol based on the RSVP, it has a high complexity and is unfriendly to IEEE 802.1.